Add a test for failing export with a reserved subset name

Author: Maxim Zhiltsov

CHANGELOG.md

@@ -38,8 +38,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   (<https://github.com/openvinotoolkit/datumaro/pull/684>,
    <https://github.com/openvinotoolkit/datumaro/pull/686>,
    <https://github.com/openvinotoolkit/datumaro/pull/687>)
-- YOLO format now supports almost any subset names, except of
-  just `train` and `valid`
+- YOLO format now supports almost any subset names, except `backup` and `classes`
+  (instead of just `train` and `valid`). The reserved names now raise an error on exporting.
   (<https://github.com/openvinotoolkit/datumaro/pull/688>)
 
 ### Deprecated

datumaro/plugins/yolo_format/converter.py

@@ -77,7 +77,7 @@ def apply(self):
                 subset_name = YoloPath.DEFAULT_SUBSET_NAME
             elif subset_name in YoloPath.RESERVED_CONFIG_KEYS:
                 raise DatasetExportError(
-                    f"Can't export '{subset_name}' subset in YOLO format, this word " "is reserved."
+                    f"Can't export '{subset_name}' subset in YOLO format, this word is reserved."
                 )
 
             subset_dir = osp.join(save_dir, "obj_%s_data" % subset_name)

tests/test_yolo_format.py

@@ -10,6 +10,7 @@
 from datumaro.components.environment import Environment
 from datumaro.components.errors import (
     AnnotationImportError,
+    DatasetExportError,
     DatasetImportError,
     InvalidAnnotationError,
     ItemImportError,
@@ -285,6 +286,25 @@ def test_can_save_and_load_with_custom_subset_name(self):
 
             compare_datasets(self, source_dataset, parsed_dataset)
 
+    @mark_requirement(Requirements.DATUM_565)
+    def test_cant_save_with_reserved_subset_name(self):
+        for subset in ["backup", "classes"]:
+
+            dataset = Dataset.from_iterable(
+                [
+                    DatasetItem(
+                        id=3,
+                        subset=subset,
+                        media=Image(data=np.ones((8, 8, 3))),
+                    ),
+                ],
+                categories=["a"],
+            )
+
+            with TestDir() as test_dir:
+                with self.assertRaisesRegex(DatasetExportError, f"Can't export '{subset}' subset"):
+                    YoloConverter.convert(dataset, test_dir)
+
     @mark_requirement(Requirements.DATUM_609)
     def test_can_save_and_load_without_path_prefix(self):
         source_dataset = Dataset.from_iterable(